Britain’s Political Destiny Will Again Be Determined by a Cameron Speech

Once again, Britain’s political destiny will be determined by a speech. In January 2013, David Cameron delivered his landmark “Bloomberg speech”—so-called because it was given in the media company’s U.K headquarters—in which he committed to delivering a referendum on the U.K.’s membership of the European Union should he still be prime minister in 2017. That speech came in response to demands from euroskeptics in his party that he clarify loose remarks made months earlier when he appeared to signal support for a referendum after...